If the dimension from the base of the camera body to the centre of the lens mount is more than 40mm, and/or the diameter of the lens barrel is more than 80mm, it is not normally possible to set a camera/lens at the NPP without modifying the dovetail clamp and rail on a Panogear/Merlin mount.

Perhaps you have modified the mount to enable you to set the centre the camera/lens on the H axis?